The invention relates to a method for opening safety doors, safety apparatus and the like. This method consists in comparing two series of identifying elements which are arranged on suitable bearings or cards to be inserted in reading units.
The prior art in the field of the control systems for opening safety doors or the like discloses some mechanical, electromechanical and electronic methods which may be computerized, for instance for codifying magnetic bands. However the said codifying operations are expensive and difficult, and involve a complicate laying and a constant maintenance by skilled personnel. Moreover in general these systems present fixed combinations. Therefore these combinations are not modifiable in practice, unless persons skilled in this field intervene to that effect. In other systems there is provided an electronic control device in which the storing is made by digitizing a predetermined combination on a keyboard. This kind of solution permits the combination to be changed when necessary, however it has the inconvenience that a user may forget a stored combination and will be no more able to actuate the opening mechanism.